It really depends on what *you* like. Technically anything that gets you moving and keeps you interested will help get the weight off, but if you don't like the workout, you won't stick with it. You might check your local video store and try a few before committing to one program. I recommend any of the Tae Bo series, something like Pilates or yoga for low impact, or any of the various aerobic workouts for cardio.
Keep in mind that you *must* address your diet if you want to get and keep the fat off your body. Exercise is great, but it's a small part of the equation. All the exercise in the world won't make up for a bad diet. Fix both parts, and you'll be lean and healthy for life.

I like Denise Austin's dvds. My favorites are her Boot Camp dvd and her Pilates ones. I really don't care for some of the other exercise dvd instructors out there! I just try them and see what I think. I know some people that like Jilian Michaels' dvd's, but I haven't tried them myself. Tae Bo is another option that should work well too. When I didn't go to the gym in the past, I would go jogging outside for about 1/2 an hour and then would come in and do Denise Austin's Pilates dvd. I got great results from doing those together! My abs got pretty flat!

Hope you find some good ones you like. I also like dance dvd's for something fun and different. I even tried Belly Dance but found I wasn't too good at it and accidentally bought the advanced one! I also like Carmen Electra's hip hop dance dvd, but once you learn the routine, it goes by so fast, so you have to do it over and over. Still fun!

I've heard really good stuff about P90X. It looks pretty tough, though...and I'm not sure of what the cost is for the whole series of DVD's, but I know of a few people that rave about the results they got from it.

P90X is not for beginners though. It's a really great program for someone with a decent level of fitness and exercise background, but if you're just starting, the workouts are too difficult and intense (and require equipment - weights or bands and a pullup bar).

Yes, I understand that P90X is not for beginners...but the OP did not state in her post whether she was a beginner or not...so I mentioned it just in case she might be looking for something more "advanced".